Westminster: Armed police arrest 'knifeman' at gunpoint outside Houses of ParliamentWestminster is on lockdown after armed police arrested a man on suspicion of carrying a knife outside the Houses of Parliament.

Officers were spotted running towards a man outside the Houses of Parliament, before reportedly Tasering him at the gates on Friday morning.

The armed officers were spotted running towards St Stephen's Gate after a commotion was heard.

The incident is not thought to be terror related.

The man arrested outside the gates to Parliament
A Met Police spokesman said: "At 11.10am on Friday, 16 June, a man was detained near to the Palace of Westminster.

"The man - aged in his 30s - was arrested on suspicion of possession of a knife.

Picture have begun to emerge online of the man, wearing a grey hoodie, being held against railings as he is arrested by officers.

The 'knifeman' being arrested outside Westminster (Harriet Line/PA )
Joe Murphy, political editor of the Evening Standard, said that there were shouts of "knife knife knife" and a man was brought down with a Taser.

In March, PC Keith Palmer was brutally stabbed to death by terrorist Khalid Masood outside Parliament.

Security around Westminster was tightened following the attack by Masood, who was shot dead after fatally as he guarded Carriage Gate.

A permanent barrier has been erected to protect pedestrians on Westminster Bridge, where Masoood also murdered four people and injured more than 50 others by mounting the pavement in a car at 70mph.

A Parliamentary spokesman said: "We are aware of an incident outside the Palace of Westminster, which is being dealt with by the Metropolitan Police."